import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;

public class UdpEchoServe {
    private static DatagramSocket socket=null;
    public UdpEchoServe(int port) throws SocketException {
        socket=new DatagramSocket( port);
    }
    public void statr() throws IOException{
        System.out.println("服务器启动");
        while (true){
            DatagramPacket requestPacket=new DatagramPacket(new byte[4096],4096);
            socket.receive(requestPacket);
            //读取客户端的请求并解析
            String request=new String(requestPacket.getData(),0, requestPacket.getLength());
            String response =process(request);
            DatagramPacket responsePacket=new DatagramPacket(response.getBytes(),response.getBytes().length,
                    requestPacket.getSocketAddress());
            socket.send(responsePacket);

            //打印日志
            System.out.printf("[%s:%d] rep=%s ,resp=%s\n",requestPacket.getAddress(),requestPacket.getPort(),request,response);
        }
    }
    private String process(String request){
        return request;
    }

    public static void main(String[] args) throws IOException {
        UdpEchoServe udpEchoServe=new UdpEchoServe(9090);
        udpEchoServe.statr();
    }
}
